program main

!*****************************************************************************80
!
!! r8vm_test() tests r8vm().
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    28 August 2022
!
!  Author:
!
!    John Burkardt
!
  implicit none

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'r8vm_test():'
  write ( *, '(a)' ) '  FORTRAN90 version:'
  write ( *, '(a)' ) '  Test r8vm().'

  call r8ge_to_r8vm_test ( )

  call r8vm_det_test ( )
  call r8vm_indicator_test ( )
  call r8vm_mtv_test ( )
  call r8vm_mv_test ( )
  call r8vm_print_test ( )
  call r8vm_print_some_test ( )
  call r8vm_random_test ( )
  call r8vm_sl_test ( )
  call r8vm_slt_test ( )
  call r8vm_to_r8ge_test ( )
  call r8vm_zeros_test ( )
!
!  Terminate.
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'r8vm_test():'
  write ( *, '(a)' ) '  Normal end of execution.'
  write ( *, '(a)' ) ' '
  call timestamp ( )

  stop 0
end
subroutine r8ge_to_r8vm_test ( )

!*****************************************************************************80
!
!! R8GE_TO_R8VM_TEST tests R8GE_TO_R8VM.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    24 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: m = 5
  integer, parameter :: n = 4

  real ( kind = rk ) a_ge(m,n)
  real ( kind = rk ) a_vm(n)
  integer seed

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8GE_TO_R8VM_TEST'
  write ( *, '(a)' ) '  R8GE_TO_R8VM converts an R8GE matrix to R8VM format.'

  seed = 123456789
  call r8ge_random ( m, n, seed, a_ge )

  call r8ge_print ( m, n, a_ge, '  The random R8GE matrix:' )

  call r8ge_to_r8vm ( m, n, a_ge, a_vm )

  call r8vm_print ( m, n, a_vm, '  The R8VM matrix' )

  return
end
subroutine r8vm_det_test ( )

!*****************************************************************************80
!
!! R8VM_DET_TEST tests R8VM_DET.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    25 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: n = 5

  real ( kind = rk ) a(n)
  real ( kind = rk ) det1
  real ( kind = rk ) det2

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_DET_TEST'
  write ( *, '(a)' ) '  R8VM_DET, determinant of a Vandermonde matrix.'
  write ( *, '(a)' ) ' '
  write ( *, '(a,i8)' ) '  Matrix order N = ', n
!
!  Set the matrix.
!
  call r8vm_indicator ( n, n, a )

  call r8vm_print ( n, n, a, '  The Vandermonde matrix:' )
!
!  Compute the determinant.
!
  call r8vm_det ( n, a, det1 )
!
!  Compare to exact value.
!
  call r8vm_indicator_det ( n, det2 )

  write ( *, '(a)' ) ' '
  write ( *, '(a,g14.6)' ) '  R8VM_DET    = ', det1
  write ( *, '(a,g14.6)' ) '  Exact value = ', det2

  return
end
subroutine r8vm_indicator_test ( )

!*****************************************************************************80
!
!! R8VM_INDICATOR_TEST tests R8VM_INDICATOR.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: m = 5
  integer, parameter :: n = 4

  real ( kind = rk ) a(m,n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_INDICATOR_TEST'
  write ( *, '(a)' ) '  R8VM_INDICATOR sets an indicator matrix in R8VM format.'

  call r8vm_indicator ( m, n, a )

  call r8vm_print ( m, n, a, '  The R8VM indicator matrix:' )
 
  return
end
subroutine r8vm_mtv_test ( )

!*****************************************************************************80
!
!! R8VM_MTV_TEST tests R8VM_MTV.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: n = 5

  real ( kind = rk ) a(n)
  real ( kind = rk ) b(n)
  integer seed
  real ( kind = rk ) x(n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_MTV_TEST'
  write ( *, '(a)' ) '  R8VM_MTV computes b=A''*x, where A is an R8VM matrix.'
!
!  Set A.
!
  seed = 123456789
  call r8vm_random ( n, n, seed, a )
!
!  Set X.
!
  call r8vec_indicator1 ( n, x )
!
!  Compute b=A'*x.
!
  call r8vm_mtv ( n, n, a, x, b )

  call r8vec_print ( n, b, '  b=A''*x' )
 
  return
end
subroutine r8vm_mv_test ( )

!*****************************************************************************80
!
!! R8VM_MV_TEST tests R8VM_MV.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: n = 5

  real ( kind = rk ) a(n)
  real ( kind = rk ) b(n)
  integer seed
  real ( kind = rk ) x(n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_MV_TEST'
  write ( *, '(a)' ) '  R8VM_MV computes b=A*x, where A is an R8VM matrix.'
!
!  Set A.
!
  seed = 123456789
  call r8vm_random ( n, n, seed, a )
!
!  Set X.
!
  call r8vec_indicator1 ( n, x )
!
!  Compute b=A*x.
!
  call r8vm_mv ( n, n, a, x, b )

  call r8vec_print ( n, b, '  b=A*x' )
 
  return
end
subroutine r8vm_print_test ( )

!*****************************************************************************80
!
!! R8VM_PRINT_TEST tests R8VM_PRINT.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: m = 5
  integer, parameter :: n = 4

  real ( kind = rk ) a(m,n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_PRINT_TEST'
  write ( *, '(a)' ) '  R8VM_PRINT prints an R8VM format.'

  call r8vm_indicator ( m, n, a )

  call r8vm_print ( m, n, a, '  The R8VM matrix:' )
 
  return
end
subroutine r8vm_print_some_test ( )

!*****************************************************************************80
!
!! R8VM_PRINT_SOME_TEST tests R8VM_PRINT_SOME.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: m = 5
  integer, parameter :: n = 4

  real ( kind = rk ) a(m,n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_PRINT_SOME_TEST'
  write ( *, '(a)' ) '  R8VM_PRINTSOME prints some of an R8VM format.'

  call r8vm_indicator ( m, n, a )

  call r8vm_print_some ( m, n, a, 2, 2, 5, 4, '  Rows 2-5, Cols 2:4' )
 
  return
end
subroutine r8vm_random_test ( )

!*****************************************************************************80
!
!! R8VM_RANDOM_TEST tests R8VM_RANDOM.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: m = 5
  integer, parameter :: n = 4

  real ( kind = rk ) a(n)
  integer seed

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_RANDOM_TEST'
  write ( *, '(a)' ) '  R8VM_RANDOM randomizes an R8VM matrix.'

  seed = 123456789
  call r8vm_random ( m, n, seed, a )

  call r8vm_print ( m, n, a, '  The R8VM matrix:' )

  return
end
subroutine r8vm_sl_test ( )

!*****************************************************************************80
!
!! R8VM_SL_TEST tests R8VM_SL.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    18 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: n = 5

  real ( kind = rk ) a(n)
  real ( kind = rk ) b(n)
  integer info
  integer :: seed = 123456789
  real ( kind = rk ) x(n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_SL_TEST'
  write ( *, '(a)' ) '  R8VM_SL solves a Vandermonde system.'
  write ( *, '(a)' ) ' '
  write ( *, '(a,i8)' ) '  Matrix order N = ', n
!
!  Set the matrix.
!
  call r8vm_random ( n, n, seed, a )
!
!  Set the desired solution.
!
  call r8vec_indicator1 ( n, x )
!
!  Compute the corresponding right hand side.
!
  call r8vm_mv ( n, n, a, x, b )
!
!  Solve the linear system.
!
  call r8vm_sl ( n, a, b, x, info )

  call r8vec_print_some ( n, x, 10, '  Solution:' )
 
  return
end
subroutine r8vm_slt_test ( )

!*****************************************************************************80
!
!! R8VM_SLT_TEST tests R8VM_SLT.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    18 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: n = 5

  real ( kind = rk ) a(n)
  real ( kind = rk ) b(n)
  integer info
  integer :: seed = 123456789
  real ( kind = rk ) x(n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_SLT_TEST'
  write ( *, '(a)' ) '  R8VM_SLT solves a transposed Vandermonde system.'
  write ( *, '(a)' ) ' '
  write ( *, '(a,i8)' ) '  Matrix order N = ', n
!
!  Set the matrix.
!
  call r8vm_random ( n, n, seed, a )
!
!  Set the desired solution.
!
  call r8vec_indicator1 ( n, x )
!
!  Compute the corresponding right hand side.
!
  call r8vm_mtv ( n, n, a, x, b )
!
!  Solve the linear system.
!
  call r8vm_slt ( n, a, b, x, info )

  call r8vec_print_some ( n, x, 10, '  Solution to transposed system:' )

  return
end
subroutine r8vm_to_r8ge_test ( )

!*****************************************************************************80
!
!! R8VM_TO_R8GE_TEST tests R8VM_TO_R8GE.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: m = 5
  integer, parameter :: n = 4

  real ( kind = rk ) a_ge(m,n)
  real ( kind = rk ) a_vm(n)
  integer :: seed = 123456789

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_TO_R8GE_TEST'
  write ( *, '(a)' ) '  R8VM_TO_R8GE converts an R8VM matrix to R8GE format.'

  call r8vm_random ( m, n, seed, a_vm )

  call r8vm_print ( m, n, a_vm, '  The random R8VM matrix:' )

  call r8vm_to_r8ge ( m, n, a_vm, a_ge )

  call r8ge_print ( m, n, a_ge, '  The R8GE matrix' )

  return
end
subroutine r8vm_zeros_test ( )

!*****************************************************************************80
!
!! R8VM_ZEROS_TEST tests R8VM_ZEROS.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 August 2015
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: m = 5
  integer, parameter :: n = 4

  real ( kind = rk ) a(m,n)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R8VM_ZEROS_TEST'
  write ( *, '(a)' ) '  R8VM_ZEROS zeros out a matrix in R8VM format.'

  call r8vm_zeros ( m, n, a )

  call r8vm_print ( m, n, a, '  The zero R8VM matrix:' )
 
  return
end
subroutine timestamp ( )

!*****************************************************************************80
!
!! TIMESTAMP prints the current YMDHMS date as a time stamp.
!
!  Example:
!
!    31 May 2001   9:45:54.872 AM
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    18 May 2013
!
!  Author:
!
!    John Burkardt
!
  implicit none

  character ( len = 8 ) ampm
  integer d
  integer h
  integer m
  integer mm
  character ( len = 9 ), parameter, dimension(12) :: month = (/ &
    'January  ', 'February ', 'March    ', 'April    ', &
    'May      ', 'June     ', 'July     ', 'August   ', &
    'September', 'October  ', 'November ', 'December ' /)
  integer n
  integer s
  integer values(8)
  integer y

  call date_and_time ( values = values )

  y = values(1)
  m = values(2)
  d = values(3)
  h = values(5)
  n = values(6)
  s = values(7)
  mm = values(8)

  if ( h < 12 ) then
    ampm = 'AM'
  else if ( h == 12 ) then
    if ( n == 0 .and. s == 0 ) then
      ampm = 'Noon'
    else
      ampm = 'PM'
    end if
  else
    h = h - 12
    if ( h < 12 ) then
      ampm = 'PM'
    else if ( h == 12 ) then
      if ( n == 0 .and. s == 0 ) then
        ampm = 'Midnight'
      else
        ampm = 'AM'
      end if
    end if
  end if

  write ( *, '(i2.2,1x,a,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) &
    d, trim ( month(m) ), y, h, ':', n, ':', s, '.', mm, trim ( ampm )

  return
end